Neil Lennon has admitted to mixed emotions over the non-appearance of Lionel Messi for Barcelona in their Group H match at Celtic Park on Tuesday night.

Messi has not travelled to Scotland because of a thigh injury, thereby denying Celtic another chance to face the world player of the year. Although Lennon, the Scottish champions' manager, conceded an element of worry had vanished, he also revealed a counter-emotion. "It is six and half a dozen," he said. "I'm delighted for selfish reasons he's not playing. For the game itself, the occasion, I'm a bit gutted that he's not playing. I wanted his shirt."

The more serious business now concerns the likelihood of Celtic having to handle other star performers, such as Neymar. "I think any team would be less effective if they lost a Messi," Lennon said. "So Barcelona are no different. He's huge. His contribution has been incredible, really.

"But if you look at the games where he hasn't played, I think they've won the majority of them anyway. I think there will be players desperate to play. They can't keep relying on him to pull it out of the bag all the time. Whether Neymar, Cesc Fábregas, they'll all be wanting to prove a point."

Lennon has challenged his players to follow in the footsteps of Tony Watt and achieve the hero status which arrives from scoring a decisive goal against Barcelona. Watt, who is on loan at the Belgian club Lierse, got Celtic's second in a 2-1 win in Glasgow last November. With Barcelona back on Champions League business, the manager has urged his squad to garner inspiration from the teenager's late intervention that night.

"I said to the players this morning: 'Do you think Tony Watt woke up that day thinking he was going to be forever etched in the club's history, the most talked-about teenager in Europe at the time? No, because anything can happen on any given night.'

"It was Tony's night. I want somebody else to do it now. I want somebody else to get the headlines that Tony did."

Lennon claimed his "hands are a little bit tied" in terms of selection, with the absence of Joe Ledley from the midfield a particular blow. Still, last year's win came despite Lennon being denied the services of two key players – Scott Brown and Gary Hooper – through illness and injury respectively.

Experiences of last season, clearly, have offered hope. "I dare to dream – oh yes," Lennon said. "Whether we can do it or not, I don't know, but we'll do everything we possibly can to do that.

"We're at home, which always gives us an advantage no matter who we're playing and it can really lift you to another level – and that's what I'm hoping the atmosphere and the occasion will do again."

Fábregas seems certain to play in Messi's false No9 position. "Obviously Leo is the best player in the world and you will obviously miss a player of that talent," said the former Arsenal captain. "He can win a game at any moment. But you cannot put your head down and feel sorry for yourself."